1. Field of the Invention
The subject apparatus and methods for use generally relate to an androgynous, reconfigurable, closed loop feedback controlled, low impact mating system and assembly with load sensing electromagnetic capture ring. More particularly, the apparatus relates to a load sensing, electromagnetic mating system. Still more particularly, the invention relates to a mating assembly and system having a reconfigurable control system that permits a load sensing ring with an electromagnetic capture mechanism to “softly” capture and mate two structures or vehicles together.
2. Additional Background
Mating systems permit two structures or vehicles to be coupled together. For instance, the assignee of the subject invention uses mating systems to mate one spacecraft to another in orbit around the Earth. The International Space Station (ISS) currently under construction in space has a mating system to permit the Space Transport System (STS), also referred to as the “Shuttle,” to mate to the ISS. Crew, equipment, supplies, and other types of cargo then can be transferred from one vehicle to the other through the mating system tunnel.
Most mating systems use a mechanical structure comprising latches, hooks and other mechanisms. Generally, there are two different ways of mating vehicles together, either docking or berthing. “Docking” occurs when a free-flying vehicle, such as the Space Shuttle, under its own control maneuvers into the capture envelope and then into contact with the docking assembly of another vehicle, such as the Space Station. “Berthing” occurs when an externally attached device such as a Remote Manipulator System (RMS), which is structurally grounded to one vehicle such as the Space Station, attaches to the other vehicle and maneuvers into the capture envelope and then into contact with the Space Station mating assembly. Docking or berthing two vehicles requires that each vehicle have a mating assembly. To dock two vehicles using a conventional mechanical mating assembly, the vehicles must be pressed together with sufficient force to re-align the soft capture ring and to trip the mechanical soft capture latches, hooks, or etc. on the respective docking assemblies, thereby coupling the two docking assemblies. In a terrestrial application, this action is analogous to two train cars coupling. Train cars can be coupled only if one car is pushed against the other car with enough force to open and then close the mechanical coupling assembly.
The following discussion details the primary phases in any mating scenario. First is the “approach” phase wherein a vehicle moves into a capture envelope. A capture envelope is a predetermined area surrounding a mating assembly into which a pilot or remote control must guide a vehicle before docking/berthing can be effected. Second is the “aligment” phase wherein the two vehicles to be mated establish a soft capture ring alignment with one another. This phase has traditionally been accomplished by driving vehicles together to force capture ring alignment using passive guides during mating or by realigning using RMS visual cues to correct for misalignments. Third is the “capture” phase which is accomplished by forcing capture latches to hold the vehicles together or by “reach around and grab arms” to capture the mating interface during berthing. Fourth is the “attenuation” phase, wherein the dynamic energy and residual motion of the separate vehicles is absorbed by the combined assembly. Fifth is the “retraction” phase where residual misalignments are nullified and the mating mechanism is retracted to bring the mating sealing interfaces in contact. The final phase is the “structural mating” phase. There, structural latches are engaged to provide a rigid structural interface and to compress and pre-load the seals to facilitate the maintenance of a pressurized volume.
With prior mechanical mating assemblies, the action of forcing two vehicles together, particularly in space, can result in damage to one or both of the vehicles or sensitive systems and components due to the high forces required to actuate capture mechanisms when mating. Further, forcing the vehicles together can ruin vibration sensitive experiments, such as crystal growth experiments, that may be performed on one or both of the vehicles. There is a need for a mating system that can minimize or eliminate the potential for structural damage and vibration caused by conventional mating systems.
The assignee of the subject apparatus led the development of a first generation androgynous, reconfigurable, closed loop feedback controlled low impact docking system described in U.S. Pat. No. 6,354,540, issued on Mar. 12, 2002 to Lewis et al. The subject apparatus encompasses a second generation androgynous, reconfigurable, closed loop feedback controlled low impact docking system.
Despite the advantages a mating system would provide, to date no such mating system is known to exist (outside the subject apparatus and the apparatus described in U.S. Pat. No. 6,354,540) that provides low force mating or that can accomplish both docking and berthing operations.